The invention relates to a regulating system for controlling the gas/air mixture of gas burners.
Regulating systems for gas burners serve to provide a gas/air mixture, that is, they serve to feed a gas flow and a combustion-air flow to a burner. In this case, the gas flow through a gas valve can be set as a function of the combustion-air pressure. Such regulating systems have been disclosed by DE 24 27 819 B2, Austrian Patent 190 195 and De 37 07 883 C1.
Regulating systems for gas burners are known in which the transmission ratio between gas pressure and combustion-air pressure or between gas flow and combustion air flow is variable. In all the known regulating systems, the requisite pressure measurement is carried out by means of a diaphragm, that is pneumatically. However, this pneumatic method has a large number of disadvantages, which all together restrict the range of application of known regulating systems. Thus the hysteresis properties of the diaphragm and the forces acting between the diaphragm and the gas valve restrict the working range and thus the range of application. Furthermore, the interplay between the requisite small actuating forces and the operating tolerances of the diaphragm, as a result of disturbances such as temperature fluctuations or the like, restricts the range of application of known regulating systems.
Against this background, the problem underlying the present invention is to provide a regulating system for gas burners which avoids the abovementioned disadvantages and thus has a greater range of application.
This problem is solved by a regulating system for gas burners that controls gas flow based on the air flow and the pressures in the gas flow and air flow ducts.
Further advantageous refinements of the invention follow. A preferred exemplary embodiment of the invention is explained in more detail below with reference to the drawing.